I'm building an uber-number crunching box for a guy. He wants the best in everything, so naturaly I recomended an Athlon MP machine. he had a few choice words to say about the dual MPs, and wanted a single Athlon instead. He wouldn't tell me WHY, other than "I've heard things". Is Athlon MP a good choice? Are there weird issues under various OS's? (this box will be running dual Win2K/Linux). -Brian